Tee-nut setting machines are known in prior art. These machines are designed to set a Tee-nut or the like, of the type having a flange head, a threaded sleeve and an open lower end on the sleeve, in a hole in a workpiece. The Tee-nut is set in a hole in the workpiece and is secured to the workpiece by spikes formed integrally with the Tee-nut. One major drawback of these machines is that the setting of the Tee-nut is not completely secure, and they can become displaced in subsequent use.
In one machine, the lower open end of the Tee-nut is deformed by splitting it into two or more portions and these portions are bent outwardly to hold the lower end of the nut secure. However, this leads to damages of the internal threading of the Tee-nut. Accordingly, special Tee-nuts were made in which the lower end was formed with an enlarged counter bore without threading. This counter bore could then be split open, without damaging the thread. This was difficult to regulate, and the Tee-nut was often split at its lower end, before it was fully inserted. Such special Tee-nuts were also costly to manufacture.